Respiratory apparatus



2 Sheets-Sheet 1 N. F. HOSFORD RESPIRATORY APPARATUS July 31, 1962 FiledDec.

D R &m 0 S T O m H VF. mN A M R O N ATTORNEY July 31, 1962 N. F. HOSFORDRESPIRATORY APPARATUS 2 Sheets-Sheet 2 Filed Dec. 23, 1957 l/l/l/AHWA r.izitt! r 3 m B FIG. 3

INVENTOR. NORMAN F. HOSFORD ATTORNEY hired; r tes l tent @fie dfid'fldlPatented duly 31, 11952 3,9410%} REdPiRATQRY APEARAT'UQE Norman F.Hosford, Davenport, lowa, amignor to The Bendix Corporation, acorporation of Delaware Filed Dec. 23, 1957, Ser. No. 704,791 3 Claims.(Cl. 13763) This invention relates to respiratory apparatus andparticularly to respiratory gas flow regulators used in connection withface masks.

An object of the invention is to provide a novel, miniature, lightweight regulator suitable for mounting on the mask. Another object is toprovide an improved mask and regulator assembly.

Where the mask and the regulator are separated, utilization of thepressure of exhaled gas in effecting flow control in the regulator wouldrequire a second large bore conduit connection from the mask to theregulator. Another object of the invention is to provide a novelregulator and a mask and regulator combination in which gas flow controlin response to both inhalation and exhalation pressure is entirelypractical.

While the invention provides a miniature regulator, the job it mustperform is as big as ever; and another object of the invention is toprovide a novel regulator having improved gas conservationcharacteristics, coupled with ability to satisfy the widest range offlow rates on inhalation demand. One object is to provide improved meansfor sensing exhalation pressure and inhalation suction, and another isto provide rapid valve action in response to the pressures sensed.Another object is to provide a regulator in which supply outlet andexhaled gas inlet openings may be located in close proximity on a faceof the regulator which can be disposed directly in front of the wearersmouth.

Another important object of the invention is to provide a regulatorconstruction which is easy and relatively inexpensive to manufacture.Often, in attempting to reduce manufacturing costs, it is necessary tocompromise on a design suitable only for that segment of the market inwhich sales potential is greatest. Thus many respira tory gas regulatorsin the past have provided a given set of functions and are not readilymodified to include more or fewer functions.

An object of this invention is to provide a regulator construction whichis readily modified to include or exclude certain functions which arenot required to be performed in various applications of the regulator.

Certain of these and other objects and advantages of the invention whichwill be apparent, are realized in part by the provision of asectionalized construction in which the various regulator functions areachieved in the separate sections. Further, the regulator is arrangedfor coordinated control'of supply and exhaust gas flow through theregulator passages arranged to open to the interior of the mask by meansfor alternately ope. ing and closing those passages in response toinhalation and exhalation pressures.

Thus the sectionalization is both physical and functional. Certainfunctions are required in all applications of the regulator; and these,reduction of supply pressure and primary supply control in accordancewith demand, are provided in the main section of the regulator. Controlof the discharge of exhaled gas is accomplished in another section ofthe regulator advantageously located at the front of the main sectionwhere it will be exposed to the exhaled gas. Pressure breathing, whichis provided as a function of atmospheric pressure, is advantageouslycontrolled in a section at the rear of the main section and exposed tothe atmosphere. In addition to permitting location of the variousregulator mechanisms at the points where their respective controlconditions are best sensed, the sectionalization by functions makes itpossible to house these mechanisms in separable body sections of theregulator.

When so separated the main section is independently useful as a demandregulator which is provided with peripheral mask attaching means and maybe disposed in an opening in a mask. Attachment of the exhaust gascontrol section, which advantageously also comprises peripheral maskattaching means, to the front of said main section results in anintegrated demand supply and exhaust regulator. Attachment of thepressure breathing section to the main body section results in acombined demand and pressure breathing regulator. vention provides aminiature regulator arranged for mounting directly on the mask and whichis complete in that it provides demand regulation, exhaust gas controland pressure breathing control. It permits elimination of exhaust gascontrol where the mask is provided with separate means for providingsuch control, elimination of pressure breathing control where thisfunction is not required, or elimination of both exhaust gas control andpressure breathing control, Without any change in the main section ofthe regulator.

The coordination between the sections is such that the relation betweenthe demand regulation and pressure breathing control sections is thesame whether or not either the exhaled gas section or a separateexhausting control means are employed. Similarly, the relation betweenthe exhaled gas section and the demand regulation section is unchangedby the presence or absence of the pressure breathing control section.

Another object of the invention is to provide a regulator in whichcontrol of the discharge of exhaled gas, main supply control, andpressure breathing control are provided in front, central and rearsections of the regulator respectively. Another object is to provide aregulator in which these sections are separable.

Certain embodiments of the invention are illustrated in the accompanyingdrawing, it being understood that various modifications of theembodiments illustrated, and other embodiments, may be made withoutdeparting from the spirit of the invention or the scope of the appendedclaims.

In the drawings:

FIG. 1 is a view incentral section of a gas flow regulator embodying theinvention, and showing a fragment of the face mask;

FIG. 2 is a sectional view taken on line 22 of the regulator of FIG. 1;and

FIG. 3 is a view in central axial section of a modified form of the gasflow regulator showing fragments of the face mask.

Referring to FIG. 1, the substantially cylindrical regulator 2% isassembled to a mask 21 so that its front face 22 is disposed in themasks breathing chamber 23. The supply and exhaust check valves arelocated toward the front, and the demand diaphragm and aneroid arelocated toward the back of the regulator. The main and pilot or reliefvalve assembly is disposed in the centerof the unit.

The gas regulator section 25 has a large circular recess 27 formed inits rear face and has a cylinder 29 extending axially from the frontface 36 of the regulator section 25. A second, shorter cylinder 31,concentric with and spaced outwardly from cylinder 29, also extendsforwardly from face 13% of regulator section 25.

The cylinder 29 defines a cylinder bore 33 which continues throughregulator section 25 almost to the flat bottom of recess 27 terminatingat a cylinder end wall 34. A reciprocally movable cylindrical'piston 36is disposed within the cylinder bore 33 and its back end forms a mainvalve head 35 which is fitted with a head 37.

Thus the in- 3 The main valveseat 38 is formed by a frustoconical boss39- and having an axial seat opening 40 connecting the cylinder bore 33with recess 27.

The forward end of the cylinder bore 33 is sealed by a cap 45, which asshown, may be. screwed to the end of cylinder wall 29. The spaces .46and 47 within the cylinder bore, ahead and in back of piston 36, areutilized as main valve'closing andopening pressure chambersrespectively. Pressure is supplied by source gas entering the openingchamber 47 at inlet 43 and leaking past the loose-fitting piston 36 intoclosing chamber 46.

Means are provided for biasing piston 36 rearwardly into position toclose the main valve 3738 and for relieving the pressure in chamber 46,whereupon pressure in opening chamber 47 displaces the piston to openthe main valve. These means, as shown in FIG. 1, may comprise a pressurerelief passage 50 extending axially through. piston 36 and head 37 andcommunicating with seat opening 40. A restriction in this passage, iforms a shoulder 151 which serves as the seat of the relief valve. Therelief valve head 52, which may be spherical, as shown, is fixed to astem 53 which slides in a guide hole 54in the cap 45. The stem 53extends through and is fixed to a spring gland 61. A bias spring 55 inchamber 46, bearing at one end against cap 45 and against gland 61 atthe other end, biases the relief valve and the main valve towardclosure.

' Means are provided for actuating the relief valve in responsetopressure changes in breathing chamber 23. In the form illustrated thiscomprises a slender actuating rod 56 whioh extends from its connectionto the center of demand diaphragm 57, through an opening in blast shield58, through main seat opening 40 and main head 37 into pressure reliefpassage 50, where its end just touches the relief valve head 52 when thedemand diaphragm issin the normal position illustrated in FIG. 1. Thedemand diaphragm overlies recess 27, its resilient margins being turnedinwardly over the end of regulator section 25 and terminating in aninturned rim 59, which is wedged into an annular circumferential recess60 in the wall otf-the regulator section. V v

The function of the blast shield 58 is to prevent the gas flowingthrough the main valve 37-38 from impinging on the demand diaphragm andthus affecting diaphragm action, and tosdirect it instead toward aplurality of supply passages 64, formed through regulator body 25 andspaced around the piston bore 33. As shown in FIG. 1,

the shield 58 may comprise a circular plate overlying the tin'gthe'kinetic action of the gas flow. 'Ihe openings are advantageouslyarrangedsoathat gas in the demand chamber will be drawn or. aspiratedfrom chamber 65 to haust port 85 in the wall of the regulator body. Atthe, end of exhalation, compression spring 74 returns the diaphragm 67into sealing engagement with the exhaust valve a suitable degree by thestream of respiratory gas which regulator section 25, in the regionbetween cylinder 29 and the-projecting cylinder 31, to the interior of acupshaped valve diaphragm 67. This diaphragm is part of both the exhaustand supply check valves and may comprise, as shown, a circular end wall68 and cylindrical side walls 69 extending toward'front face .36 andterminating in an enlarged rim disposed between the inner wall 71 of'theexhaust section 72 of the regulator and 68 distended with the inner cup7-3 pressed against the diaphragm end wall 68.

Respiratory gas entering the cup-shaped diaphragm 67 through the supplypassages 64 flows into the breathing chamber 23 of the mask through aplurality of perforations 75 in inner cup 73 and slits 76, in thediaphragm 67; The perforations 75 and slits 76, as best illustrated inFIG. 2, may be arranged in a circle concentric with the regulator axisand formed in the end Walls of the inner cup and diaphragm respectively.7

The pressure of the respiratory gas applied to the diaphragm end wall 63through perforations 75 lifts the end Wall away from the inner cup,permitting gas flow to the slits 76 which are spread open by the gaspressure. Slits 76 are oifset anguluarly from perforations75, overlyingsolid portions of the inner cup 73, and so are prevented from openinginwardly in response to exhalation pressure. Thus the diaphragm slitsand inner cup 73 form a check valve in the respiratory gas supplycircuit.

Advantageously the inner cup 73 is held tightly against the diphragm endwall 68 by clamping means which may,

as shown, comprise a circular, cup-shaped clampingplate' 77 secured tothe inner cup 73 by a rivet 73 connecting their centers, and having anannular rim pressing the diaphragm to the inner cup along a lineencircling the diaphragm slits 76. A plurality of openings 79 in the endwall of the clamping plate permits the passage of respiratory gas fromslits 76 to the mask breathing chamber 23.

In addition to its function of providing a check valve in therespiratory gas supply circuit, the valve diaphragm 67 serves as thevalve head of an exhaust valve. A ring- 80 threaded into the forward endof the exhaust section 72 of the regulator is provided with an inwardlyturned annular flange81. An annular rim -32 at the inner margin of thisflange engages the outer margin of the diaphragm end wall 68 and servesas the exhaust valve seat.

In operation ofthe regulator illustrated in FIGS. l and 2, duringexhalation the pressure of exhaled gas this action the diaphragm endwall 68 is moved away from the exhaust valve seat 82 and exhaled gasflows into a recess in the space surrounding diaphragm 67, from whenceit is discharged to the atmosphere through an exseat 82, in whichposition it is shown in FIG. 1.

During inhalation, suction created in the breathing:

chamber 23 of the mask draws the diaphragm end wall 68 away from innercup 73 to deform the end wall at slits 76 to permit residual gas to bedrawn out of the demand chamber 65 via louvers 66, supply passages 64,inner cup perforations 75, diaphragm slits 76, and clamping plateopenings 79 into the breathing chamber 23.

The resulting pressure reduction in demand chamber 65 effectsdisplacement of the demand diaphragm '57 to carry actuator rod 56 in adirection tomove the relief valve head 52 against bias spring 55 to openthe relief" valve. Upon opening of the relief valve, gas flows from themain valve closing pressure chamber 46 through pressure relief passage50 and the main valve seat opening 40. The pressure in chamber 46 havingbeen relieved,

gas pressure in the main-valveopening pressure chamber '47, acting onthe rear face of piston 36, forces the; piston forward to carrymain'valve head 37 away from its seat 38. Respiratory gas entering theregulator at inlet 48 flows through the main seat opening 40.

This gas, and the gas which was released from the main valve closingpressure chamber 47, is directed by blast shield 58 to supply passages64, through which it flows to the interior of valve diaphragm 67 andthrough inner cup perforations 75, diaphragm slits 76, and clampingplate openings 79 to the mask breathing chamber 23.

The degree to which the main valve is opened is determined by the degreeof inhalation suction in the demand chamber 23 as measured by thedisplacement of demand diaphragm 57. The displacement of the latterdetermines the spacing betv een the pilot valve head 52 and the mainvalve seat 38. The pressure in chamber 47 at the front of piston 36 isdetermined by the flow rate into the chamber past the piston and out ofthe chamber past the relief valve. The pressure in chamber 46 at therear of the piston is determined by the flow rate through the mainvalve. Piston 36 moves between a rearward position in which the mainvalve is closed and a forward position in which the relief valve isclosed, to that intermediate position in which pressure at opposite endsof the piston is balanced. This arrangement automatically adjusts theoxygen supply to varied inhalation demands.

As the gas flows under the blast shield 58 past louvers 66, an aspiratorelfect proportional to the rate of gas flow results in Withdrawal of gasfrom the demand chamber 65 and a reduction in pressure there as long asthe inhalation demand at the breathing chamber 23 continues. At the endof inhalation, gas pressure builds up in the supply circuit and istransmitted through louvers 66 to return the demand diaphragm, andconsequently the main and relief valves, to the normal position in whichthey are shown. I

This embodiment of the regulator advantageously includes removable meansfor supplying gas to the mask under pressure. This means may comprise ananeroid which expands with altitude and, at altitudes where pressurebreathing is required, engages and displaces the demand diaphragm in thedirection to open the relief valve. In the form selected forillustration in FIG. 1, a rear or pressure breathing control section 87is threaded to the back end of the regulator section 25. An expansiblediaphragm 88 is disposed in section 87 and is secured to its end wall90. Air in the space between expansible diaphragm 83 and demanddiaphragm 57 escapes through openings 91 in the side Walls of thepressure breathing control section 87, and the diaphragm 88 expands, asatmospheric pressure is reduced with altitude. At a selected altitudethe expanding diaphragm 88 engages the demand diaphragm 57 as shown. Asaltitude is increased further, expansion of diaphragm 8 8 will causerelief valve 51-52 to open. This in turn results in the opening of themain valve and gas flows to the mask, inhalation suction not beingrequired, and the mask wearers breathing is inverted. During forcedexhalation, the pressure of exhaled gas closes the supply circuit checkvalve, comprised of the slits 76 in valve diaphragm 67, and pressurebuilding up in the supply circuit forces demand diaphragm 57 outwardlyagainst the force of diaphragm 88, causing the relief and main valves toclose.

The regulator of FIG. 3, like the regulator shown in FIGS. 1 and 2, issectionalized both structurally and functionally. The central or gasregulator section includes the main supply and pressure relief valvesand the demand diaphragm and demand chamber; and its function is toreduce the pressure of the respiratory gas and control its flow inaccordance with demand for gas. The rear or pressure breathing controlsection houses an aneroid which operates the demand diaphragm to providepressure breathing at high altitudes and the front or exhaust sectioncontrols the discharge of exhaled gas. As in the earlier describedregulator, this one has its supply and exhaust openings at its frontface.

In FIG. 3, the cylindrical gas regulator section 1713 comprises portions171 and 172, main valve 173-, main valve actuating diaphragm 174, mainvalve openings and closing pressure chambers 175- and 176 respectively,pilot valve 177, lever system 178, demand chamber 179, demand diaphragm186* and pressure transmitting passage 131. The pressure transmittingpassage 18 1 and the supply passage 182 open at the front face 183 ofthe regulator section 170.

The exhaust section houses two check vflves, one in the supply circuitand the other in the exhaust circuit. In the form shown, the exhaustsection 184 comprises a generally cylindrical peripheral Wall from whichan integrally formed annular projection 185 extends centrally,terminating at its free margin in a rearwardly projecting annular lipwhich serves as a seat 136 for the exhaust valve.

The supply check valve may be formed within the exhaust valve head 187as shown. This structure is disposed centrally in exhaust section 184-behind exhaust valve seat 186, where it is supported by an annulardiaphragm 19 2. The outer margin194 of this support diaphragm 192 isclamped between the rear face of section 184 and the front face 183 ofregulator section 171. The inner margin 191 of the annular supportdiaphragm 192 is secured to the substantially cylindrical outer rim 186of the exhaust valve head 137. A series of spaced radially extendingspokes connect the rim to the central hub 193.

The supply check valve may comprise, as shown, a resilient disk 196which is connected at its center to the hub 193 so that it overlies theforward side of the spokes 190 with its outer margin 197 in seatingengagement with an annular shoulder or seat surface 198 formed on theinner surface of the rim 188. This valve is normally closed, the valvedisk 1% having resilience to maintain its outer margin 197 against theshoulder or seat 198.

During exhalation in the breathing chamber 199 of the mask 2%, on whichthe regulator is secured by mounting means comprising the walls of theregulator and exhaust sections of the regulator, the supply check valveis held closed by exhalation pressure applied to disk 1% to hold itsmargins 197 in engagement with seat surface 198. But this pressure ondisk 196 displaces the exhaust valve head 187 against the bias of spring195 to carry it away from its seat 186, whereupon the exhaled gas flowspast the valve head 187 into the space 2111 between the diaphragm 192and projection 185. From here it flows to the atmosphere through anexhaust passage comprising a port 202 connected directly to theatmosphere.

At the end of exhalation all of the regulator valves are returned to thenormal position in which they are illustrated in FIG. 3. Duringinhalation, suction in the breathing chamber 199 holds the exhaust valve186-187 closed but lifts the margins 197 of the supply valve disk 196away from seat surface 198. Residual gas in pressure transmittingpassage 18 1 and demand chamber 179 is drawn into the mask. The effectof the pressure reduction in the demand chamber 179 is to displacedemand diaphragm 189, actuate the lever system 178 to open the reliefvalve 177, and reduce the pressure in chamber 176, displacing diaphragm17 4 and opening the main valve 173. Upon opening of the main valve 173,respiratory gas flows through supply passage 182 and through the checkvalve 197-198 into the breathing chamber 199.

The various elements of the regulator and mask shown in FIG. 3, althoughthey diifer in form, are in function and coordination, like thecorresponding similarly titled components of the regulator illustratedin FIGS. 1 and 2. This is also true of the pressure breathing controlsection designated 265 in FIG. 3 and which includes a housing 296,threaded on the back end of the gas regulator portion 172, and ananeroid assembly 297. The latter expands with altitude and at a selectedaltitude engages and displaces the demand diaphragm, whereuponrespiratory gas is supplied to the mask under pressure as explained inconnection with the previously described regulator.

' sage, a movable demand diaphragm in a Wall of said chamber, meansresponsive to diaphragm movement for s actuating the valve, and meansfor varying the demand charnber pressurein accordance with flow rate insaid passage, comprising means including a shield separating the demandchamber from the passage for shielding the diaphragm from gas flow inthe passage and aspirator means formed in the shield for aspirating gasfrom the demand chamber in accordance with the rate of gasflow in saidpassage. I

2. The invention defined in claim 1 including a pressure breathingcontrol section connected to said regulator section including pressuresensitive means expansible to exert pressure on and move said diaphragmat selected atmospheric pressures.

' 3. In a sectionalized gas flow' regulator of the type including a mainsupply valve actuated in response to move- I 'mentof a diaphragm and apilot valve operated by movement or" another diaphragm for altering thepressure applied to the first mentioned diaphragm, in combination:

a a regulator body including first, second, and third substantiallycylindrical and separable body portions serially arranged in axialalignment, adjacent end faces of the F first interposed between saidfirst andsecond body portions and separating the cavity jointly'formedby their recesses into individual chambers and the second interposedbetween said second and third body portions and separating the cavityjointly formed by their recesses into individual chambers; a. firstpassagewaydefined by said second body portion connecting its recesses; asecond passageway defined by said first and second body portions andextending from the chamber formed by said second body portion and saidsecond diaphragm through the second body,

portion and the first body portion to the face of the first body portionopposite saidrsecond body portion; a supply passageway formed in saidbodyopening at the end face of said body at said first body portion andcommunicating with each of the chambers. separated by saidfirstdiaphragm; a pilot valve. sensitive to movement of said seconddiaphragm in saidfirst passageway; a main supply valvein: said supplypassageway operatively connected to said first diaphragm; and means forintroducing respiratory gas into'said supply passageway on the side ofsaid main supply valve away from said opening and toward said chambersseparated bylsaid first diaphragm.

' References Cited in the file of this patent UNITED STATES PATENTSGoodner Dec. 22, 1959

